Superconducting inertial apparatus



Nov. 30, 1965 c, THOMPSON, JR 3,220,262

SUPERCONDUGTING INERTIAL APPARATUS Original Filed July .24, 1959 5Sheets-Sheet 1 DIQEQTION or TRAVEL 22 9 DETECT'lON 28 AMPLIFIER CONTROLAMPL! F ER F\LT'E.R a. COMPENSATION NETWORK POFHON DETECTOR WAVE. 36GENERATOR, 1 H S EuuM [APPLY 2 ATON\\C/ CLOCK 58 To G\N\BAL 2 COURSE 4 zSTABLE PLATFORM DEVIAT\ON GEORGL' C. 77/0MP504/ jk.

\HPUT AMPUFER INVENTOR.

VEPHCLE CONTROL A7TORNEY G. c. THOMPSON, JR 3,220,262

SUPERCONDUCTING INERTIAL APPARATUS Nov. 30, 1965 Original Filed July 24,1959 5 Sheets-Sheet 5 1 63) 62 f I To 64 VEJ-HCLE DETEQTON CHARGING dCONTROL & CONTROL DETECTOR 5W AMPLIFIER 7|b MICROWAVE GENERATOR 22DETECTOR 7O AMPLIHER 4 69a GEORGE lilo/p50 fie INVENTOR.

720. 7m l8 BY W/ J19" 5W MICROWAVE AZ GENERATOR 9% I ATToRA/Eys UnitedStates Patent 3 220,262 SUPERCONDUCTING INERTIAL APPARATUS George C.Thompson, Jr., Simi, Calif., assignor to TRW Inc., a corporation of OhioContinuatiaon of application Ser. No. 829,368, July 24, 1959. Thisapplication Feb. 8, 1963, Ser. No. 257,818 9 Claims. (Cl. 73505) Thisinvention relates to superconducting inertial apparatus and moreparticularly to an inertial reference system provided withsuperconducting cavities for continuously supplying yaw, pitch and rollreferences without interruption. This application is a continuation ofmy copending application Superconducting Inertial Apparatus, SerialNumber 829,368, filed July 24, 1959, now forfeited.

Some present well known systems capable of providing inertial guidanceutilize either spinning masses or vibrating masses capable of operationin substantially fixed relative planes for the purpose of providingreferences for guidance purposes. However, due to spinning mass bearingfriction or internal resistance of resilient members supporting thevibrating masses, a substantial amount of precession occurs causingerrors in the guidance system reference. Many steps have been taken toreduce errors due to bearing friction such as, for example, providing adrive means for driving the outer races of the support bearings for aspinning mass in opposite directions. Although this provides someimproved operational conditions, it is obvious that some bearingfriction still exists and, therefore, causes the introduction of errorinto the guidance system.

It is, therefore, an object of this invention to provide a guidancesystem utilizing radio frequency waves within superconductive cavitiesas a continuous reference for each of the three major axes.

It is another object of this invention to provide a guidance systemprovided with a plurality of sets of duplicate superconducting cavitiesfor duplicate directional references to allow for control by one set ofcavities while recharging takes place in another set.

It is another object of this invention to provide an energy injectionand detection means for each superconducting cavity that is capable ofinjection and detection through the cavity wall.

It is still another object of this invention to provide a means forrapidly switching an area in each superconducting sphere betweenresistive and superconducting condition to provide energy injection anddetection operation.

It is still another object of this invention to provide a means forrapidly switching a plurality of areas in each superconducting spherebetween resistive and superconducting condition to provide energyinjection and detection operation.

Other objects, purposes and characteristic features will become clear asthe description of the invention progresses.

In practicing this invention, there is provided a plurality ofsuperconductive enclosures forming cavities capable of receiving radiofrequency energy which is propagated through the wall of each cavity toform node positions within each cavity. The enclosures are positioned infixed relationship with each other to represent the yaw, pitch and rollaxes and arranged to provide continuous reference. Each cavity isprovided wit-h a detector means for detecting the node position througheach cavity wall and to provide an output in response to a deviation ofthe detector means away from the node position. With the enclosuresforming the cavities being freely gimbaled, and with each enclosurebeing provided with a drive mechanism for repositioning each in responseto a deviation detection by its detector means, it is only necessary toprovide a drive mechanism output for vehicle control in response torepositioning of each enclosure and drive means upon deviation detectionby each detector. It should pointed out at this time that the only causeof deviation of the enclosure cavities with respect to the injectedradio frequency wave within each cavity is the movement of eachenclosure about its radio frequency wave upon vehicle deviation from thedesired course. In view of the fact that no bearing friction or windageexists within the enclosure cavities, no error is introduced in thereference waveforms.

FIGURE 1 is a diagrammatic view of three spheres having waveformsinjected therein at the proper positions to provide the three basicreference axes herein designated X, Y and Z;

FIGURE 2 is a view of a typical superconductive sphere representing oneof the planes and showing waveform injection, node detection and atypical control system;

FIGURE '3 is a diagrammatic view of three superconducting spheresmounted on a gimbaled platform and provided with a typical controlsystem;

FIGURE 4 is a diagrammatic representation of the use of two systems forcontrol and recharging;

FIGURE 5 is a view of another superconducting sphere provided with acommon injection and detection opening;

FIGURE 6 is a graph showing the relationship existing at one instantbetween the electric field and the magnetic field within a sphere suchas the sphere of FIGURE 5; and

FIGURE 7 is a cutaway view removed from a portion of one of thesuperconductive spheres showing an inject-or and detector involving theprinciples of this invention.

In each of the several views similar parts bear like referencecharacters.

It has been known for many years that the electrical resistance of metaldecreases with the lowering of temperature. With further experiments,however, it has been determined that certain materials apparently reducetheir electrical resistance to approximately zero at temperaturesapproaching absolute zero. This phenomenon has been referred to as thesuperconductive qualities of the materials being used. By utilizing thissuperconducting quality in forming a cavity by an enclosure such as asphere and then injecting into the cavity a radio frequency wave havinga half wave length equal to substantially the diameter of the cavity\-2.29a, where a is the radius of the sphere), little or no energy isexpended by the waveform energy that is propagated within thesuperconductive cavity. Long periods after the injection of the energywithin the cavity, little or no attenuation of the energy would bedetected.

There are several kinds of nodes; for example, there can be an electricfield node, a magnetic field node as well as a current node. For thesystems illustrated herein and graphically demonstrated in FIGURES 5 and6 and for the wave propagation shown which is of the lowest order withthe electric field shown flowing in the direction of the arrows, themaximum of the electric field will exist along the axis with theelectric field falling to zero at the surface of this sphere. At thesame time the magnetic field shown by the dots dispersed within thefield area will be at zero along the axis and the maximum in an areaadjacent the intersurfaoe of the sphere.

If we now consider the schematic representation of FIGURE 1 it can beseen that if a radio frequency is injected into a spherical cavity suchas formed by the sphere 1 at a point 2 and if the sphere 1 iselectrically perfect, a magnetic field node will exist along a lineindicated by the arrow 3. At this same point, a current node will existin the surface of the sphere at one of the points 3. It is at one of thepoints 3 that a detector is introduced through the sphere 1 and sincethe detector is basically at the node position, little or no losses.will occur. In addition to the sphere 1, if we also provide a sphere 4with an energy injection point indicated at 5, a magnetic field nodewill exist along the line indicated by the arrow 6. Since thepoint ofinjection in this sphere 4 is displaced with respect to the point ofinjection in the sphere 1, this sphere is capable of operation in adifferent plane. In order to provide complete directional control, athird sphere is provided for detection in a third reference plane. Forthis purpose, the sphere 7 is provided having an injection point at 8and a node detection for the magnetic field indicated by the arrows 9.With the three spheres, the three necessary reference planes areprovided giving roll, pitch and yaw detection.

In FIGURE 1, the three spheres are shown mounted on gimbals supported ona single reference support or table T in order to clearly show theinter-related cooperation of the spheres. The gimbals for each of thespheres are provided to prevent excessive energy losses from the spheresdue to a deviation of the vehicle from its desired course as will beexplained hereinafter.

In order to understand clearly what is necessary to provide a radiofrequency waveform for one detection plane, a more detailed structure ispresented in FIGURE 2 and is explained hereinafter. In FIGURE 2, themeans for injection and detection of energy into and out of,respectively, the sphere 1 is shown to be in the form of waveguides. Itis pointed out, however, that the energy may be injected and detected byother structures such as the heater and loop of FIGURE which will beexplained in more detail hereinafter.

The sphere 1 shown in FIGURE 2 is preferably formed of material capableof superconducting operation such as lead and capable of providing ahigh Q resonant chamber. Since, however, lead is inherently weak instructural strength, it is necessary to provide a structural sphere ofsome stronger material provided with a lead coating on the interiorthereof of sufficient depth to provide for an energy change in the lead,when it goes superconducting, that is greater than the energy injectedin radio frequency form. Although the cavity is herein shown as asphere, it is pointed out that other shaped cavities also could be used.

Since the superconductive sphere is only superconducting at temperaturesapproaching absolute zero, it is necessary to supply this sphere with acooling medium such as liquid helium. In order to contain the liquidhelium about the superconductive sphere 1, an enclosing outer sphere 10spaced from the sphere 1, is provided. The area between the inner sphere1 and its adjacent outer sphere 10 is then filled with helium from ahelium supply 11 piped into the cavity formed by the spheres 1 and 10through suitable insulated pipes 12 and 13. Since the spheres 1 and 10are supercooled to a point near absolute zero, it is necessary toinsulate the spheres to prevent excessive losses. For protection againstexcessive thermal losses, a third sphere 14 is positioned about thesphere 10, and spaced therefrom. The area between the spheres 10 and 14is then evacuated and sealed, thus forming a suitable vacuum bottle forpreventing the losses.

Since a perfect electrical sphere can not readily be formed, it isnecessary to provide suitable electrical shims 15 for adjusting theelectrical quantities of the superconducting sphere 1 to be electricallyperfect to an injected waveform. The shims are made available throughsuitable sealing plugs 16 in the evacuated sphere 14.

Several different modes of wave propagation within a sphere arepossible. The one illustrated in the present application is commonlyreferred to as the lowest order of wave propagation within a sphere andis used as an illustration only since it is the simplest to demonstrateand understand. This mode of operation may be excited in severaldifferent ways such as by means of a magnetic coil, a dipole fed by acoaxial cable or a slot fed by a waveguide. Whatever the method used forexciting the sphere the feed mechanism should be made to disappear inorder to reduce the losses that would be encountered by the mechanismremaining within the sphere.

In order to position the node of an injection waveform along the nodeline 3 of the superconducting sphere 1, the point of wave propagation orinjection should be displaced therefrom by and at a point that isrelatively high in energy level in the magnetic field such as shown bythe curve H in FIGURE 6. As shown in FIGURE 2, the point of injection 2would be nearly at the maximum field potential level as shown by thecurve H. The method of injection shown in FIGURE 2 involves the use ofan opening 2 provided with a suitable waveguide 17 connected to anenergy supply or microwave generator 18. In order to maintain thesuperconducting qualities of the sphere after injection of energy intothe sphere, a suitable sealing plug 19 is provided and is movable fromits open position, as represented in FIGURE 2, to a position forming asubstantially smooth internal surface for the sphere 1. The plug valve19 is moved by an actuator 20 connected to the plug valve 19 through asuitable link 21.

It, therefore, can be seen that with the plug valve 19 in its retractedposition, energy can be emitted from the microwave generator 18 throughthe waveguide 17 into the sphere 1 and immediately following the energyentrance into the sphere the plug valve 19 can be rapidly moved to itssealing position. With the plug in position the energy is prevented frombeing expended back through the waveguide opening thus keeping losses toa minimum. In addition, the adjustable shims 15 can be moved in and outas is necessary to form an electrically perfect sphere.

At this point, we now have the radio frequency wave established withthesuperconductive sphere or container 1 with its node along the line 3.In order to provide a means of sensing movement of the superconductivesphere about the injected radio frequency energy, a detector amplifier22 having a waveguide 23 entering through the sphere 1 along the nodeline 3 is provided. Waveguide 23 is provided with suitable insulation 24for reducing thermal conduction losses to a minimum.

As long as the sphere 1 is maintained in the exact position occupiedduring waveform injection, the waveguide 23 will be positioned along thenode line 3. If, however, the sphere is rotated, causing detectorwaveguide 23 displacement from the node position, energy will be passedthrough the waveguide 23 to the detection amplifier 22. A deviation ofextremely small amounts from the node position will result in energydetection by the detection amplifier 22. v I

In order to keep losses to a' minimum in the injected wave within thesphere 1, a suitable drive means or motor 25 is provided for returningthe sphere to node position as soon as deviation occurs. The motor 25 isconnected through suitable mechanical gearing linkage 26 to a spheresupporting platform T which is gimbaled for free directional movementsuch as shown in FIGURE 3. Under some conditions the sphere may beseparately gimbaled (not shown). The motor 25 is driven in response todeviation detection by the detection amplifier 22 which provides anoutput through the output path 28 to a phase sensitive control amplifier29. The control amplifier 29 is provided with a control input from asuitable reference means such as an atomic clock 30 over an input path31.

A typical atomic clock is described in principle in the article byHarold Lyons appearing on page 71 of the February 1957 ScientificAmerican. As described in this article, atomic clocks have been madeusing ammonia and cesium. In addition, Maser clocks have also been madeusing ammonia.

The purpose of the atomic clock 30 is to provide an exact reference fordetecting phase relationship of the signal from the detector amplifier22 for determining the direction of rotation of motor 25. In order toprovide a phase or error reference, the atomic clock is used as areference for the microwave generator 18 through a timing control path32. The output signal of the detection amplifier 22 is compared with theoutput signal of the atomic clock 30 resulting in an output over thepath 33 to suitable filters 34, capable of providing an output over path35 to the motor 25. Movement of the motor 25 is then detected by asuitable deviation detector 36 which provides an output signal over thepath 37 to a summation amplifier 38 capable of providing an outputsignal over the output path 39 for vehicle control.

The summation amplifier 38 is provided with an additional input path 40for the purpose of directing a vehicle deviation from the original path.To provide this control an input signal is provided over the path 40 tothe summation amplifier 38 which results in a vehicle output controlover the path 39. As the vehicle begins to deviate from its originalpath the detector amplifier 22 detects the deviation and causes thecontrol amplifier 29 to drive the motor 25 to reposition the sphere 1and detector amplifier 22 to the node line 3. Movement of the motor 25results in a signal from the deviation detector 36 to the summationamplifier 38. This signal, to the amplifier 38 over the path 37,eventually balances the input signal from the path 49 when the directeddeviation of the vehicle from the original path has been satisfied.

The energy within the sphere 1, however, is not dissipated due to thenew course since the detection amplifier 22 has been repositioned to thenode of the injected waveform.

It is pointed out at this time that the detection amplifier 22 can bedisplaced in two different planes falling along the node line 3 thusresulting in a signal being detected by the amplifier 22. If, however,the system used is one involving a desired detection in one plane only,the electrical circuitry is such that the phase of the detected signalas compared to the atomic clock signal can be passed only when thedeviation is in the proper plane. In order to prevent energy losses dueto detection amplifier movement along the unwanted plane, the desiredsystem utilizes a gimbaled platform T with detection spheres for each ofthe other planes also mounted thereon. With this arrangement deviationfrom node position in any plane will be rapidly corrected with detectionresulting only in the desired sphere for each plane.

Referring now to FIGURE 3, there is shown a complete guidance systemutilizing three superconductive spheres gimbaled for three axesrotation. In addition to the previously described pitch axis sphere 1and its detector amplifier 22 there is provided for the roll detectionsuperconductive sphere 4 a suitable evacuated shell such as a sphere 41and a suitable detector amplifier 42. Similarly, the yaw detectionsphere 7 is provided with a vacuum shell, such as a sphere 43, and asuitable detector amplifier 44. The microwave generator and plug valvecontrol mechanisms are located within a suitable container 45interconnecting the three spheres and will not be shown in detail sincea typical schematic arrangement for one sphere has been shown anddescribed hereinbefore.

The control system shown in the system of FIGURE 3, is a complete systemfor three sensing spheres similar to the single sphere described inconnection with FIG- URE 2. The system provides control by each of thespheres for the axes shown in FIGURE 3. For example, the pitch controlsphere is provided with a pitch control amplifier 29, a filtercompensation network 34, a pitch motor 25, a pitch summation amplifier38 and a vehicle control output 39. Likewise, the roll axis controlsphere 4 is provided with a detection amplifier 42, a roll controlamplifier 46, suitable filters 47, a roll control motor 48,

a roll summation amplifier 49 and a roll control output path 50. The yawcontrol is provided by the yaw control sphere 7, its detection amplifier44, a yaw control amplifier 51, suitable filters 52, a yaw control motor53, a yaw summation amplifier 54, and a yaw output vehicle control path55. Each detector sphere and its control system acts to maintainplatform T stabilized along its respective axes and with reference tothe sphere injected energy by providing output signals to the axis drivemotors which provide outputs to the vehicle control system over therespective output circuits 39, 50 and 55. The atomic clock providesreference signals for each of the control amplifiers and for themicrowave generator or generators within the container 45.

The platform T is supported for pivotal movement on a suitable gimbal 56which is in turn pivotally supported on a second support gimbal 57 whichis also pivotally supported on a suitable vehicle support 58. The axesof rotation for the platform and each of the gimbals represent each ofthe three planes of sensing.

The diagrammatic view of FIGURE 4 represents the principle of providinga plurality of guidance groups described as two separate guidance systemgroups or systems which may be needed for long and extensive flightcontrol. The sensing superconductive spheres 59, 60 and 61 provideduplicates for the sensing spheres 1, 4 and 7 respectively. This figurediagrammatically represents detecting and control as being accomplishedby connecting the detecting circuits 62 to spheres 1, 4 and 7 throughthe control switch 63, while at the same time supplying charging energythrough the charging circuit 64 to the spheres 59, 60 and 61.

At a suitable time period as determined by experience, the switch 63 canbe reversed to provide guidance by the spheres 59, 60 and 61 whilecharging of the spheres 1, 4 and 7 takes place. The alternate chargingand control of each of the groups can provide vehicle control over asubstantially unlimited course.

In order to simplify the superconductive sphere for the purpose ofmaintaining energy losses to a minimum, it may be desirable to providemicrowave injection and detection through the same device. The structureof FIG- URE 5 shows one arrangement capable of accomplishing thisresult.

If we assume again that the sphere shown in this figure is the pitchcontrol sphere 1, it can be seen that the sphere 1 is again providedwith the surrounding spheres 10 and 14 for the purpose of providinghelium cooling and evacuated zones as described in FIGURE 2. The heliumsupply, lines 12 and 13, are shown in phantom lines since it isnecessary to provide the helium through a pivot platform supportprovided by the pivot 65. The pivot 65 is necessary in order to move thewaveguide from injection position to detection position for the twodifferent modes of operation on its platform (not shown in this figure).This repositioning is provided by a suitable control drive means ormotor 66 provided with a pinion gear 67 meshed with a suitable linearrack type gear 68 mounted along a portion of the periphery of theevacuated shell 14.

The injection and detection device shown in FIGURE 5 comprises a thermalor heater element 69 for switching an area 70 in the sphere 1 betweensuperconducting and resistive condition. In resistive condition the area70 appears as an opening or window to a varying frequency. For thisreason a resonant frequency having a wave length A-2.29 times the radiusof the sphere can be propagated in each sphere. In view of this fact aninjection and detector coil (or loop) 71 is positioned adjacent the area70 to provide injection and detection of energy within the sphere 1through the area 70. During injection of energy, such as microwaveenergy the selector switch 72 connects the microwave energy source 18 tothe loop 71. At the same time the direct current source terminal 74 isconnected to the heater element 69 by the switch 72. It is pointed outthat the loop '71 may also serve as the heater as well as the injectorwith the result that the separate heater 69 could be eliminated.

If it is assumed that the heater 69 and loop 71 is energized by thegenerator 18 causing the injection of a microwave frequency to takeplace it is only necessary to interrupt the direct current by the switch72 to cause the resistive area 70 to be again switched tosuper-conducting state. This operation is completed with little or noenergy loss. The injection operation establishes a wave patternrepresented in FIGURE by the typical electric field lines 75 and themagnetic field dots 76. After ceasing injection operation the motor 66is energized to drive the sphere clockwise for 90. When in the 90position from that shown in FIGURE 5, the switch 72 is again operated tosupply direct current to the heater 69 to provide the resistive area orwindow in the sphere 1 at the magnetic node position of the injectedwave. The loop 71 is now in a position to receive energy from theinjected microwave. If the sphere 1 is displaced in a direction movingthe loop 71 away from node position, through deviation of the vehiclefrom its intended course, energy is then induced in the loop 71 andsupplied to the amplifier 22.

FIGURE 6 is a graph showing schematically the energy levels found withinthe sphere of FIGURE 5, at one instant. As shown here the ordinate axisrepresents the energy axis while the abscissa directly corresponds tothe diameter of the sphere. With H representing the magnetic field and Erepresenting the electric field, it can be seen that the sphere as shownin FIGURE 5 would have zero magnetic field along a center axis that ishorizontal in the position shown in FIGURE 5 while the electric fieldrepresented by E is at a maximum at this point. It is also clear thatthe electric field falls to zero at the top and bottom of the sphere aspositioned in FIGURE 5 while the magnetic field is just slightly belowits highest potential point. It should further be clear, therefore, thatafter injection of energy by loop 71 into the sphere 1, and rotation ofthe loop 71 to a position to 90 from the position shown in FIGURE 5, theloop 71 would be at the point of zero magnetic field potential, sincethe sphere is rotated about the propagated wave therein.

It is pointed out that the motor 66 moves the sphere 1 and its outershells 10 to 14 through 90 only, and at this time is deenergized andmaintains the sphere in this 90 position with respect to the platformuntil such time energy injection is again necessary. At this time themotor 66 is again energized in the opposite direction to return thesphere to the original position for energy injection. The motor controlcircuit is not shown since any well known control would be suitable.

The pivot point 65, is not shown in detail since any suitable pivot maybe used. It is pointed out, however, that in addition to the heliumsupply pipes a passage 71 is necessary for the supply and return ofpower and signal energy. 1

In some conditions it may be desirable to have the heater 69 and loop 71subjected to a limited supply of cooling helium for faster switching.With the elements 69 and 71 being continuously cooled it is necessarythat they be constructed of a material remaining resistive at all times.

The arrangement of FIGURE 7 sets forth separate injector and detectorareas for each sphere, which is necessary for a system such as shown inFIGURES 2 and 3. The injection area 70 in the sphere 1 is made resistiveor non-resistive by the energization or deenergization of the heater 69aat the desired switch 72a selected time. During resistive periods of thearea 70 the microwave source 18 is supplying energy to the loop 71a.

Positioned 90 from the injection area 70 is a detection controlledresistive area 70b. The area 76b is also provided with a pickup loop 71band a heater 6%, with the heater being controlled by the switch 72b. Theoperation of the separate injector and detector devices is the same asthe operation of the device of FIGURE 5 when in its injection anddetection positions, respectively, except for the fact that the twofunctions are separated into two devices with a single path switch foreach heater. The loops 71a and 71b could also be switch controlled,however, no operation can take place until the areas 70 and 70b are maderesistive.

While there has been described what is at present considered a preferredembodiment of the invention, it will be obvious to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the invention, and it is aimed in the appended claims tocover all such changes and modifications as fall within the true spiritand scope of the invention.

What is claimed is:

1. An inertial guidance system comprising two guidance groups, eachgroup having a plurality of superconducting means each of which definesa movable electrical cavity, energy injection means associated with eachof said plurality of superconducting means for injecting energy in eachsaid cavity to establish a resonant wave having a predictable magneticnode position, energy detection means mounted on each cavity andinitially positioned at the originally established resonant wavemagnetic node position, switch control means for providing energyinjection in one of said groups while energy detection is taking placein the other of said groups, said energy injection and detection meanscomprising a thermal means for causing a portion of each of saidsuperconducting means to become resistive and loop means associated Witheach said thermal means for providing energy injection and detectionoperation.

2. An inertial guidance system providing a plurality of guidance groups,each group having a plurality of superconducting means, each of saidplurality of superconducting means defining a movable cavity, energyinjection means associated with each of said plurality ofsuperconducting means for injecting waveform energy in each said cavityto establish a resonant wave having a predictable magnetic nodeposition, energy detection means mounted on each cavity and initiallypositioned at the originally established resonant wave magnetic nodeposition, switching control means for providing energy injection in oneof said plurality groups while energy detection is taking place inanother of said plurality of groups, said energy injection and detectionmeans comprising a thermal means for causing a portion of each of saidsuperconducting means to become resistive and loop means associated witheach said thermal means for providing energy injection and detectionoperation.

3. In an inertial guidance system comprising a plurality ofsuperconducting means defining a plurality of movable superconductingcavities, energy injection means associated with each of said pluralityof superconducting means for injecting waveform energy in each cavity toestablish a resonant wave having a predictable magnetic node position,energy detection means mounted on each cavity and initially positionedat the originally established resonant wave magnetic node position, saidenergy injection and detection means comprising, a means for causing atleast one area in each container to become resistive, flux producing anddetecting means positioned adjacent'said resistive area, and means forenergizing said injection and detection means for making suchsuperconducting container areas resistive for injection and detectionpurposes.

4. In an inertial guidance system comprising a plurality ofsuperconducting means defining a plurality of movable superconductingcavities, energy injection means associated with each of said pluralityof superconducting means for injecting waveform energy in each cavity toestablish a resonant wave having a predictable magnetic node position,energy detection means mounted on each cavity and initially positionedat the originally established resonant wave magnetic node position, saidenergy injection and detection means comprising, a means for causing atleast one area in each cavity to become resistive, flux producing anddetecting means positioned adjacent said resistive area, and means forenergizing said injection and detection means for making suchsuperconducting cavity areas resistive for injection and detectionpurposes, said injection and detection means being positioned externallyof said superconducting cavity.

5. In an inertial guidance system comprising a plurality ofsuperconducting means defining a plurality of movable superconductingcavities, energy injection means associated with each of said pluralityof superconducting means for injecting waveform energy in each cavity toestablish a resonant wave having a predictable magnetic node position,energy detection means mounted on each cavity and initially positionedat the originally established resonant wave magnetic node position, saidenergy injection and detection means comprising, a means for causing atleast one area in each cavity to become resistive, flux producing anddetecting means positioned adjacent said resistive area, and means forenergizing said injection and detection means for making suchsuperconducting cavity areas resistive for injection and detectionpurposes, said injection and detection means providing electricalopenings in said superconducting cavity without providing physicalopenings therein.

6. In an inertial guidance system comprising a plurality ofsuperconducting means defining a plurality of movable superconductingcontainers forming cavities, microwave energy injection means associatedwith each of said plurality of superconducting means for injectingwaveform energy in each cavity to establish resonant waves havingmutually perpendicular node positions, energy detection means positionedon each cavity at the originally established node position for detectingmovement of the cavities about mutually perpendicular axes, said energyinjection and detection means comprising a con trol means forselectively causing at least one area in each superconducting containerto become resistive, loop means positioned adjacent said resistive areafor acting at one time to provide waveform energy injection into itsadjacent container and at another time provide energy detection of thewaveform within said container.

7. In an inertial guidance system comprising a plurality ofsuperconducting means defining a plurality of movable superconductingcontainers forming resonant cavities, energy injection means associatedwith each of said plurality of superconducting means for injectingwaveform energy in each cavity to establish resonant waves havingmutually perpendicular node positions, energy detection means positionedon each cavity at the originally established node position for detectingmovement of the cavities about mutually perpendicular axes, said energyinjection means comprising a thermal switching means for causing onearea in each superconducting container to become resistive, fluxproducing means positioned adjacent the external surface of saidresistive area, and microwave generating means connected to said fluxproducing means for inducing microwave energy within each saidcontainer.

8. In an inertial guidance system comprising a plurality ofsuperconducting means defining a plurality of movable superconductingcontainers forming resonant cavities, energy injection means associatedwith each of said plurality of superconducting means, for injectingwaveform energy in each cavity to establish resonant waves havingmutually perpendicular node positions, energy detection means positionedon each cavity at the originally established node position for detectingmovement of the cavities about mutually perpendicular axes, said energydetection means comprising thermal switching means for causing one areain each container to become resistive, flux detecting means positionedadjacent to said resistive area in each said superconducting container,detector amplifier means connected to said flux detector means forsensing any waveform energy within each said container.

9. In an inertial guidance system comprising a plurality ofsuperconducting means defining a plurality of superconducting containersforming resonant cavities, energy injection means associated with eachof said plurality of superconducting means for injecting waveform energyin each cavity to establish resonant waves having mutually perpendicularnode positions, energy detection means positioned on each cavity at theoriginally established node position for detecting movement of thecavities about mutually perpendicular axes, said energy injection meanscomprising a thermal switching means for causing one area in eachsuperconducting container to become resistive, flux producing meanspositioned adjacent the external surface of said resistive area, andmicrowave generating means connected to said flux producing means forproviding microwave energy within each said container, said energydetection means comprising second thermal switching means for causing another area in each said container to become resistive, flux detectingmeans in said energy detecting means positioned adjacent to said anotherresistive area in each said superconducting container for detectingwaveform energy in each container when the node is displaced, detectoramplifier means connected to said flux detector means.

References Cited by the Examiner UNITED STATES PATENTS 2,914,736 11/1959Young 30788.5

OTHER REFERENCES An article from Space/Aeronautics, May 1959, entitledResearchers Explore Exotic Gyros, by J. Holahan.

RICHARD C. QUEISSER, Primary Examiner.

JAMES J. GILL, Examiner.

1. AN INERTIAL GUIDANCE SYSTEM COMPRISING TWO GUIDANCE GROUPS, EACHGROUP HAVING A PLURALITY OF SUPERCONDUCTING MEANS EACH OF WHICH DEFINESA MOVABLE ELECTRICAL CAVITY, ENERGY INJECTION MEANS ASSOCIATED WITH EACHOF SAID PLURALITY OF SUPERCONDUCTING MEANS FOR INJECTING ENERGY IN EACHSAID CAVITY TO ESTABLISH A RESONANT WAVE HAVING A PREDICTABLE MAGNETICNODE POSITION, ENERGY DETECTION MEANS MOUNTED ON EACH CAVITY ANDINITIALLY POSITIONED AT THE ORIGINALLY ESTABLISHED RESONANT WAVEMAGNETIC NODE POSITION, SWITCH CONTROL MEANS FOR PROVIDING ENERGYINJECTION IN ONE OF SAID GROUPS WHILE ENERGY DETECTION IS TAKING PLACEIN THE OTHER OF SAID GROUPS, SAID ENERGY INJECTION AND DETECTION MEANSCOMPRISING A THERMAL MEANS FOR CAUSING A PORTION OF EACH OF SAIDSUPERCONDUCTING MEANS TO BECOME RESISTIVE AND LOOP MEANS ASSOCIATED WITHEACH SAID THERMAL MEANS FOR PROVIDING ENERGY INJECTION AND DETECTIONOPERATION.